The universal gaseous detonation dynamics

The present communication proposes a new scaling approach to unify the dynamics of gaseous detonations subject to wall losses in both the narrow channels and small tubes, by compiling the published experimental data of detonations in 23 different mixtures with a very large range of cellular instabilities. A kinetic induction length ${\Delta }_{i,loss}$ can be determined from the detonation velocity deficit and detailed chemistry. In order to take into account the sensitivity of the latter length to post-shock temperature fluctuations (through the reduced activation energy $\theta$), which is a partial and indirect marker of the cellular structure, and to bring out energetics (through the Chapman–Jouguet detonation Mach number $M_{CJ}$), an effective kinetic length of ${\Delta }_{i,loss}(M_{CJ}^4/{\theta }^3)$ was built and has been shown to collapse the different detonation dynamics of various gaseous mixtures, subjected to wall losses, into a single universal curve for detonation velocity deficits.

Novelty and Significance: Scaling analysis of large sets of published data of gaseous detonation experiments in narrow channels and small tubes has been made for 23 different mixtures with varied cellular instabilities and activation energies. The universal dynamics of gaseous detonations subject to wall losses in different mixtures has been achieved, for the first time, by adopting an effective kinetic length by taking into account the effect of both the activation energy and the energetics.